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International Journal of Digital Multimedia Broadcasting
Volume 2010 (2010), Article ID 645049, 13 pages
Research Article

An Evolutionary Video Assignment Optimization Technique for VOD System in Heterogeneous Environment

Department of Electronic and Information Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong

Received 8 January 2010; Accepted 21 June 2010

Academic Editor: Markus Kampmann

Copyright © 2010 King-Man Ho et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


We investigate the video assignment problem of a hierarchical Video-on-Demand (VOD) system in heterogeneous environments where different quality levels of videos can be encoded using either replication or layering. In such systems, videos are delivered to clients either through a proxy server or video broadcast/unicast channels. The objective of our work is to determine the appropriate coding strategy as well as the suitable delivery mechanism for a specific quality level of a video such that the overall system blocking probability is minimized. In order to find a near-optimal solution for such a complex video assignment problem, an evolutionary approach based on genetic algorithm (GA) is proposed. From the results, it is shown that the system performance can be significantly enhanced by efficiently coupling the various techniques.